Bochkova Olga, Khrizanforov Mikhail, Gubaidullin Aidar, Gerasimova Tatiana, Nizameev Irek, Kholin Kirill, Laskin Artem, Budnikova Yulia, Sinyashin Oleg, Mustafina Asiya
Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, Arbuzov str., 8, 420088 Kazan, Russia.
Kazan Federal University, Kremlevskaya str. 29/1, 420008 Kazan, Russia.
Nanomaterials (Basel). 2020 Jul 9;10(7):1338. doi: 10.3390/nano10071338.
The present work introduces both synthesis of silica nanoparticles doped with Co ions by means of differently modified microemulsion water-in-oil (w/o) and Stöber techniques and characterization of the hybrid nanoparticles (Co@SiO) by TEM, DLS, XRD, ICP-EOS, SAXS, UV-Vis, and UV-Vis/DR spectroscopy and electrochemical methods. The results reveal the lack of nanocrystalline dopants inside the hybrid nanoparticles, as well as no ligands, when Co ions are added to the synthetic mixtures as Co(bpy) complexes, thus pointing to coordination of Co ions with Si-O groups as main driving force of the doping. The UV-Vis/DR spectra of Co@SiO in the range of d-d transitions indicate that Stöber synthesis in greater extent than the w/o one stabilizes tetrahedral Co ions versus the octahedral ions. Both cobalt content and homogeneity of the Co distribution within Co@SiO are greatly influenced by the synthetic technique. The electrochemical behavior of Co@SiO is manifested by one oxidation and two reduction steps, which provide the basis for electrochemical response on glyphosate and HP(O)(OEt) with the LOD = 0.1 μM and the linearity within 0.1-80 μM. The Stöber Co@SiO are able to discriminate glyphosate from HP(O)(OEt), while the w/o nanoparticles are more efficient but nonselective sensors on the toxicants.
本工作介绍了通过不同改性的油包水（w/o）微乳液和施托伯技术合成掺杂钴离子的二氧化硅纳米颗粒，以及通过透射电子显微镜（TEM）、动态光散射（DLS）、X射线衍射（XRD）、电感耦合等离子体发射光谱（ICP-EOS）、小角X射线散射（SAXS）、紫外可见光谱和紫外可见漫反射光谱（UV-Vis/DR）以及电化学方法对杂化纳米颗粒（Co@SiO）进行表征。结果表明，当钴离子以Co(bpy)配合物的形式添加到合成混合物中时，杂化纳米颗粒内部不存在纳米晶掺杂剂，也没有配体，这表明钴离子与Si-O基团的配位是掺杂的主要驱动力。Co@SiO在d-d跃迁范围内的紫外可见漫反射光谱表明，与油包水合成法相比，施托伯合成法在更大程度上使四面体钴离子相对于八面体离子更稳定。合成技术对Co@SiO中的钴含量和钴分布的均匀性都有很大影响。Co@SiO的电化学行为表现为一个氧化步骤和两个还原步骤，这为对草甘膦和HP(O)(OEt)的电化学响应提供了基础，检测限为0.1 μM，线性范围为0.1 - 80 μM。施托伯法制备的Co@SiO能够区分草甘膦和HP(O)(OEt)，而油包水法制备的纳米颗粒对这些有毒物质是更高效但非选择性的传感器。
